Fragger is surely as American as they get!
Sparks I’ve been wondering about. Really, really wondering. She’s got a vaguely Central / Eastern European accent, yes, and does that stereotypical thing where she drops the indefinite article. Sometimes she sounds more German, though - including one of her taunts, which is German. Which makes me wonder if she could be, I don’t know, Swiss?
My money would be on Polish, though.
Bushwhacker is definitely not Australian. He’s also about as American as they come. Probably an NRA member and Republican voter.
Also, while Vassili’s got a Russian-sounding name, his voice sure isn’t. Which always struck me as weird. Maybe he’s a dual citizen!